Update changelog for gh-130
Reset bot's channel list on reconnect.

Closes gh-129
Fix plugin examples to use new "set" syntax for options

Closes gh-98
Support IPv6 addresses in incoming DCC SEND

DCC doesn't officially support IPv6. Some people decided to just use
the string representation of an IPv6 address in the handshake.

Note that this does not add support for outgoing DCC SEND with IPv6
addresses.

Closes gh-125
Closes gh-127
bump version to 2.0.6
Merge branch 'maint'